a - b = 7, ab = 60 হলে a2 + b2 = কত?

a - b = 7, ab = 60 হলে a² + b² = কত?

A 180

B 168

C 169

D 170

Solution

Correct Answer: Option C

a² + b²
= (a - b)² + 2ab
= (7)² + 2 × 60
= 49 + 120
= 169